Authors:Johannes Ingrisch; Michael BahnAbstract: Publication date: Available online 21 February 2018 Source:Trends in Ecology & Evolution Author(s): Johannes Ingrisch, Michael Bahn Resilience is a key concept in ecology and describes the capacity of an ecosystem to maintain its state and recover from disturbances. Numerous metrics have been applied to quantify resilience over a range of ecosystems. However, the way resilience is quantified affects the degree to which different trajectories of ecosystem recovery from disturbance are represented as ‘resilient’, precluding a comparison of disturbance responses across ecosystems and their properties and functions. To approach a broadly comparable assessment of resilience we suggest using a bivariate framework that jointly considers the disturbance impact and the recovery rate, both normalized to the undisturbed state of a system. We demonstrate the potential of the framework for attribution and integration across the various components underlying resilience.

Authors:Frédéric Thomas; Irina Kareva; Nynke Raven; Rodrigo Hamede; Pascal Pujol; Benjamin Roche; Beata UjvariAbstract: Publication date: Available online 20 February 2018 Source:Trends in Ecology & Evolution Author(s): Frédéric Thomas, Irina Kareva, Nynke Raven, Rodrigo Hamede, Pascal Pujol, Benjamin Roche, Beata Ujvari Evolved dependence is a process through which one species becomes ‘dependent’ on another following a long evolutionary history of interaction. This happens when adaptations selected in the first species for interacting lead to fitness costs when the second species is not encountered. Evolved dependence is frequent in host–parasite interactions, where hosts may achieve a higher fitness in the presence of the parasite than in its absence. Since oncogenic manifestations are (i) ubiquitous across multicellular life, (ii) involved in parasitic-like interactions with their hosts, and (iii) have effectively driven the selection of numerous adaptations, it is possible that multicellular organisms display evolved dependence in response to oncogenic processes. We provide a comprehensive overview of the topic, including the implications for cancer prevention and treatment.

Authors:Oscar Godoy; Ignasi Bartomeus; Rudolf P. Rohr; Serguei SaavedraAbstract: Publication date: Available online 19 February 2018 Source:Trends in Ecology & Evolution Author(s): Oscar Godoy, Ignasi Bartomeus, Rudolf P. Rohr, Serguei Saavedra The quest for understanding how species interactions modulate diversity has progressed by theoretical and empirical advances following niche and network theories. Yet, niche studies have been limited to describe coexistence within tropic levels despite incorporating information about multi-trophic interactions. Network approaches could address this limitation, but they have ignored the structure of species interactions within trophic levels. Here we call for the integration of niche and network theories to reach new frontiers of knowledge exploring how interactions within and across trophic levels promote species coexistence. This integration is possible due to the strong parallelisms in the historical development, ecological concepts, and associated mathematical tools of both theories. We provide a guideline to integrate this framework with observational and experimental studies.

Authors:André Frainer; Brendan G. McKie; Per-Arne Amundsen; Rune Knudsen; Kevin D. LaffertyAbstract: Publication date: Available online 15 February 2018 Source:Trends in Ecology & Evolution Author(s): André Frainer, Brendan G. McKie, Per-Arne Amundsen, Rune Knudsen, Kevin D. Lafferty Species interactions can influence ecosystem functioning by enhancing or suppressing the activities of species that drive ecosystem processes, or by causing changes in biodiversity. However, one important class of species interactions – parasitism – has been little considered in biodiversity and ecosystem functioning (BD-EF) research. Parasites might increase or decrease ecosystem processes by reducing host abundance. Parasites could also increase trait diversity by suppressing dominant species or by increasing within-host trait diversity. These different mechanisms by which parasites might affect ecosystem function pose challenges in predicting their net effects. Nonetheless, given the ubiquity of parasites, we propose that parasite–host interactions should be incorporated into the BD-EF framework.

Authors:Emily J. Schofield; Jennifer K. Rowntree; Eric Paterson; Rob W. BrookerAbstract: Publication date: Available online 9 February 2018 Source:Trends in Ecology & Evolution Author(s): Emily J. Schofield, Jennifer K. Rowntree, Eric Paterson, Rob W. Brooker Temporal dynamism of plant resource capture, and its impacts on plant–plant interactions, can have important regulatory roles in multispecies communities. For example, by modifying resource acquisition timing, plants might reduce competition and promote their coexistence. However, despite the potential wide ecological relevance of this topic, short-term (within growing season) temporal dynamism has been overlooked. This is partially a consequence of historic reliance on measures made at single points in time. We propose that with current technological advances this is a golden opportunity to study within growing season temporal dynamism of resource capture by plants in highly informative ways. We set out here an agenda for future developments in this research field, and explore how new technologies can deliver this agenda.

Authors:Kathryn C. Grabenstein; Scott A. TaylorAbstract: Publication date: Available online 3 January 2018 Source:Trends in Ecology & Evolution Author(s): Kathryn C. Grabenstein, Scott A. Taylor Hybridization between naturally co-occurring species that normally do not interbreed is being documented following anthropogenic habitat modifications for an increasing number of taxa. Here, we evaluate the mechanisms by which disturbance promotes hybridization and highlight the utility of human-caused hybridization for understanding evolution. Monitoring hybridization dynamics before, and following, disturbance over multiple timescales offers a unique opportunity to understand how disturbances alter species interactions and to pinpoint the mechanisms that cause species barriers to fail. Identifying the conditions promoting hybridization in disturbed habitats, the generality of these conditions across taxa, and the taxa most affected by human-mediated change is critical for furthering our understanding of human impacts on evolution and for informing management.

Authors:Sheela P. Turbek; Elizabeth S.C. Scordato; Rebecca J. SafranAbstract: Publication date: Available online 27 December 2017 Source:Trends in Ecology & Evolution Author(s): Sheela P. Turbek, Elizabeth S.C. Scordato, Rebecca J. Safran Seasonal journeys between breeding and non-breeding habitat are undertaken by a diverse array of animals. Parallel developments in tracking and genomic methods are enabling finer resolution of these movements and their role in the evolutionary process. Evidence from allopatric and co-occurring breeding populations indicates that variation in migratory behavior is often associated with genetic differentiation. While assortative mating and selection against hybrids due to divergent migratory phenotypes can contribute to reproductive isolation, the details of these mechanisms remain unclear. Here we identify gaps in our understanding of the role of seasonal migration in the speciation process and propose a framework to test the relative significance of reproductive barriers associated with variation in migratory behavior that might underlie population differentiation.

Authors:Pierre Mariotte; Zia Mehrabi; T. Martijn Bezemer; Gerlinde B. De Deyn; Andrew Kulmatiski; Barbara Drigo; G.F. (Ciska) Veen; Marcel G.A. van der Heijden; Paul KardolAbstract: Publication date: Available online 11 December 2017 Source:Trends in Ecology & Evolution Author(s): Pierre Mariotte, Zia Mehrabi, T. Martijn Bezemer, Gerlinde B. De Deyn, Andrew Kulmatiski, Barbara Drigo, G.F. (Ciska) Veen, Marcel G.A. van der Heijden, Paul Kardol In agricultural and natural systems researchers have demonstrated large effects of plant–soil feedback (PSF) on plant growth. However, the concepts and approaches used in these two types of systems have developed, for the most part, independently. Here, we present a conceptual framework that integrates knowledge and approaches from these two contrasting systems. We use this integrated framework to demonstrate (i) how knowledge from complex natural systems can be used to increase agricultural resource-use efficiency and productivity and (ii) how research in agricultural systems can be used to test hypotheses and approaches developed in natural systems. Using this framework, we discuss avenues for new research toward an ecologically sustainable and climate-smart future.

Authors:Andrew D. FooteAbstract: Publication date: Available online 30 November 2017 Source:Trends in Ecology & Evolution Author(s): Andrew D. Foote Sympatric speciation has been of key interest to biologists investigating how natural and sexual selection drive speciation without the confounding variable of geographic isolation. The advent of the genomic era has provided a more nuanced and quantitative understanding of the different and often complex modes of speciation by which sympatric sister taxa arose, and a reassessment of some of the most compelling empirical case studies of sympatric speciation. However, I argue that genomic studies based on contemporary populations may never be able to provide unequivocal evidence of true primary sympatric speciation, and there is a need to incorporate palaeogenomic studies into this field. This inability to robustly distinguish cases of primary and secondary ‘divergence with gene flow’ may be inconsequential, as both are useful for understanding the role of large effect barrier loci in the progression from localised genic isolation to genome-wide reproductive isolation. I argue that they can be of equivalent interest due to shared underlying mechanisms driving divergence and potentially leaving similar patterns of coalescence.

Authors:Rachel M. Germain; Jennifer L. Williams; Dolph Schluter; Amy L. AngertAbstract: Publication date: Available online 25 November 2017 Source:Trends in Ecology & Evolution Author(s): Rachel M. Germain, Jennifer L. Williams, Dolph Schluter, Amy L. Angert Character displacement is one of the most studied phenomena in evolutionary biology, yet research has narrowly focused on demonstrating whether or not displacement has occurred. We propose a new experimental approach, adopted from the coexistence literature, that directly measures interspecific competition among sympatric and allopatric populations of species. Doing so allows increased ability to (i) test predictions of character displacement without biases inherent to character-centric tests, (ii) quantify its effect on the stability of coexistence, (iii) resolve the phenotypic pathways through which competitive divergence is achieved, and (iv) perform comparative tests. Our approach extends research to forms of character displacement not readily identified by past methods and will lead to a broader understanding of its consequences for community structure.

Authors:Richard J. Hobbs; Leonie E. Valentine; Rachel J. Standish; Stephen T. JacksonAbstract: Publication date: Available online 21 November 2017 Source:Trends in Ecology & Evolution Author(s): Richard J. Hobbs, Leonie E. Valentine, Rachel J. Standish, Stephen T. Jackson Increased attention to species movement in response to environmental change highlights the need to consider changes in species distributions and altered biological assemblages. Such changes are well known from paleoecological studies, but have accelerated with ongoing pervasive human influence. In addition to species that move, some species will stay put, leading to an array of novel interactions. Species show a variety of responses that can allow movement or persistence. Conservation and restoration actions have traditionally focused on maintaining or returning species in particular places, but increasingly also include interventions that facilitate movement. Approaches are required that incorporate the fluidity of biotic assemblages into the goals set and interventions deployed.

Authors:Alexandra J.R. Carthey; Daniel T. BlumsteinAbstract: Publication date: Available online 10 November 2017 Source:Trends in Ecology & Evolution Author(s): Alexandra J.R. Carthey, Daniel T. Blumstein Through natural as well as anthropogenic processes, prey can lose historically important predators and gain novel ones. Both predator gain and loss frequently have deleterious consequences. While numerous hypotheses explain the response of individuals to novel and familiar predators, we lack a unifying conceptual model that predicts the fate of prey following the introduction of a novel or a familiar (reintroduced) predator. Using the concept of eco-evolutionary experience, we create a new framework that allows us to predict whether prey will recognize and be able to discriminate predator cues from non-predator cues and, moreover, the likely persistence outcomes for 11 different predator–prey interaction scenarios. This framework generates useful and testable predictions for ecologists, conservation scientists, and decision-makers.

Authors:Nick Colegrave; Graeme D. RuxtonAbstract: Publication date: Available online 6 November 2017 Source:Trends in Ecology & Evolution Author(s): Nick Colegrave, Graeme D. Ruxton Pseudoreplication is controversial across experimental biology. Researchers in the same field can disagree on whether a given study suffers from pseudoreplication and on to what extent any pseudoreplication undermines the value of a study. A recent survey indicated that concerns about pseudoreplication can strongly impact peer review of manuscripts submitted for publication. Here we explore controversies around pseudoreplication, identify issues requiring resolution, and in each case offer a resolution. We emphasise that having non-independence in data points and pseudoreplicating are not the same thing. Researchers should be able to demonstrate that in a given experiment they have minimised and controlled the risk of non-independence weakening their study. If they do that to the satisfaction of others, they have avoided pseudoreplication.

Authors:David B. Lindenmayer; Gene E. Likens; Jerry F. FranklinAbstract: Publication date: Available online 2 November 2017 Source:Trends in Ecology & Evolution Author(s): David B. Lindenmayer, Gene E. Likens, Jerry F. Franklin Earth observation networks (EONs) are an emerging, surveillance-based approach to environmental monitoring and research that are fundamentally different than traditional question-driven, experimentally designed approaches. There is an urgent need to find an optimal balance between these approaches and to develop new integrated initiatives that take advantage of key features of them both.

Authors:Isabelle Gounand; Eric Harvey; Chelsea J. Little; Florian AltermattAbstract: Publication date: Available online 1 November 2017 Source:Trends in Ecology & Evolution Author(s): Isabelle Gounand, Eric Harvey, Chelsea J. Little, Florian Altermatt The meta-ecosystem framework demonstrates the significance of among-ecosystem spatial flows for ecosystem dynamics and has fostered a rich body of theory. The high level of abstraction of the models, however, impedes applications to empirical systems. We argue that further understanding of spatial dynamics in natural systems strongly depends on dense exchanges between field and theory. From empiricists, more and specific quantifications of spatial flows are needed, defined by the major categories of organismal movement (dispersal, foraging, life-cycle, and migration). In parallel, the theoretical framework must account for the distinct spatial scales at which these naturally common spatial flows occur. Integrating all levels of spatial connections among landscape elements will upgrade and unify landscape and meta-ecosystem ecology into a single framework for spatial ecology.

Authors:Jakob Brodersen; David M. Post; Ole SeehausenAbstract: Publication date: Available online 30 October 2017 Source:Trends in Ecology & Evolution Author(s): Jakob Brodersen, David M. Post, Ole Seehausen The value of biodiversity is widely appreciated, but we are only beginning to understand the interplay of processes that generate biodiversity and their consequences for coevolutionary interactions. Whereas predator–prey coevolution is most often analyzed in the context of evolutionary arms races, much less has been written about how predators are affected by, and respond to, evolutionary diversification in their prey. We hypothesize here that adaptive radiation of prey may lead to diversification and potentially speciation in predators, a process that we call an upwards adaptive radiation cascade. In this paper we lay out the conceptual basis for upwards adaptive radiation cascades, explore evidence for such cascades, and finally advocate for intensified research.